A flaw was found in dnsmasq. After a reduction of internal domain-name buffer sizes, the DNSSEC validator can write a few bytes past a name buffer when converting names to and from DNS wire format. An attacker who can cause the server to validate a crafted DNSSEC response may overwrite a small amount of adjacent heap metadata. DNSSEC support is not compiled in by default and must also be enabled at runtime.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

The following measures reduce risk: 1. Do not enable --dnssec or --trust-anchor unless DNSSEC validation is required. 2. Omit -DHAVE_DNSSEC from COPTS (this is the default build). 3. If DNSSEC validation is required, restrict dnsmasq to trusted upstream resolvers.

History

Thu, 29 Oct 2026 13:00:00 +0000

Type Values Removed Values Added
Description A flaw was found in dnsmasq. After a reduction of internal domain-name buffer sizes, the DNSSEC validator can write a few bytes past a name buffer when converting names to and from DNS wire format. An attacker who can cause the server to validate a crafted DNSSEC response may overwrite a small amount of adjacent heap metadata. DNSSEC support is not compiled in by default and must also be enabled at runtime.
Title Dnsmasq: dnsmasq: heap out-of-bounds write in dnssec validator via to_wire/from_wire transforms
First Time appeared Redhat
Redhat ceph Storage
Redhat enterprise Linux
Redhat openshift
Redhat openstack
Weaknesses CWE-787
CPEs cpe:/a:redhat:ceph_storage:9
cpe:/a:redhat:openshift:4
cpe:/a:redhat:openstack:13
cpe:/a:redhat:openstack:18.0
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat ceph Storage
Redhat enterprise Linux
Redhat openshift
Redhat openstack
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-10-29T14:07:20.766Z

Reserved: 2026-09-17T14:35:34.562Z

Link: CVE-2026-93011

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-29T13:17:16.220

Modified: 2026-10-29T14:18:00.690

Link: CVE-2026-93011

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses